How to lose $7269.30

So in December of 2021, I decided to trim down out family budget by getting rid of excess channels on our TV package. When I called the support line, they asked which account I would like this applied to. I was shocked to find out that the previous account that I had with this same provider was not only still active, but was also still racking up monthly bills. Before I moved, I requested that the service be terminated and gathered up their internet and TV equipment to take to a shipping store for return. My first mistake; I did not take a picture or get a receipt of the delivery.

I immediately cancelled the old account, made it very clear what was to be done with the new account (which packages to add, drop etc.) Completely close out Account #1 (old account) effective now. Account #2 (current account) close out TV, keep internet. I was assured TV service would last until the end of the billing cycle and I was fine with that. We discussed the changes and verbally confirmed multiple times on the phone what needed to happen and to which account.

I did some research on my old account and found that the owner of the property had installed a different internet and TV provider, so it would be easy to prove that there had been no activity on the account at all.

Turns out they stopped my current account’s (account #2) TV service immediately instead of waiting for the end of the billing cycle. I once again returned the equipment (picture of the receipt this time). I was able to get the payment history of the old account which ended up being over $7200. I filed a dispute with the company in January. I provided all the details I could in the hopes of seeing any of that money back.

Jump to Tuesday. I got on their online chat and was quickly thrown into a supervisor said that if I had been charged, it was completely valid and got out of the chat as quickly as he could. I did have paperless + automatic billing enabled on the account, so I did not get any further notifications from them about the old but active account. I do accept that I should have been more active in my banking account to catch this much earlier, but I feel as though they made the first massive mistake in not cancelling the account when I asked them to back in 2018.

Just called to verify and they have no record of me stopping service.  I didn't move service from one location to another, the current service is its own separate account.

How does this pass the common sense test?